PDIK1L Antibody

Molecular Characterization of PDIK1L

PDIK1L belongs to the protein kinase superfamily, specifically the Ser/Thr protein kinase family. It is a 341-amino acid protein with a calculated molecular weight of approximately 39 kDa, which is consistently observed in experimental analyses . PDIK1L is also known by alternative names including CLIK1L and Serine/threonine-protein kinase PDIK1L, reflecting its enzymatic function and molecular relationships . The protein is encoded by the PDIK1L gene (Gene ID: 149420), which can be found in GenBank under accession number BC028713 .

PDIK1L shares significant structural and functional homology with STK35, with sequence identity of approximately 69% . This paralogy suggests evolutionary conservation of function and potentially overlapping roles in cellular processes. The kinase domain is the primary functional unit of PDIK1L, responsible for its catalytic activity in phosphorylation reactions.

Cellular Localization and Expression Patterns

PDIK1L predominantly localizes to the nucleus in various cell types, though the exact functional significance of this nuclear localization remains under investigation . This subcellular compartmentalization suggests potential roles in nuclear signaling pathways, transcriptional regulation, or nuclear structure maintenance.

Expression analysis reveals that PDIK1L is widely distributed across multiple tissues and organs. Notably, PDIK1L is abundantly expressed in endometriotic cells and moderately expressed in stromal fibroblasts . The protein may be released into the abdominal cavity during menstrual cycles, potentially eliciting autoantibody reactions that could be relevant to certain pathological conditions .

Available Antibody Types and Selection Criteria

Researchers have access to various PDIK1L antibodies with different properties suitable for distinct experimental applications. The primary types include:

• Polyclonal antibodies: These provide broad epitope recognition and are commonly used in initial characterization studies. Examples include rabbit polyclonal antibodies that target different regions of the PDIK1L protein .

• Monoclonal antibodies: These offer high specificity to single epitopes, such as the mouse monoclonal 4B7 antibody targeting amino acids 72-308 .

Selection of the appropriate antibody should be based on:

• Target region specificity (e.g., internal region, N-terminal, C-terminal)

• Species reactivity needs (human, mouse, rat, or wider cross-reactivity)

• Intended application (Western blot, ELISA, immunohistochemistry)

• Isotype requirements and detection system compatibility

Optimizing Antibody Applications in Research

PDIK1L antibodies have been validated for multiple experimental techniques:

For optimal Western blot results, researchers should consider:

• Sample preparation: Most effective results observed with tissue lysates from spleen tissue

• Blocking conditions: BSA can improve specificity in some applications

• Detection systems: Both chemiluminescence and fluorescence systems are compatible

• Positive controls: Mouse or rat spleen tissue provides reliable positive controls

Troubleshooting Common Technical Challenges

When working with PDIK1L antibodies, researchers frequently encounter several challenges:

• Non-specific binding: This can be minimized by optimizing antibody dilution and washing steps. The affinity-purified antibodies like ABIN3186373 (purified using epitope-specific immunogen) demonstrate improved specificity .

• Signal intensity variations: These can result from differences in PDIK1L expression levels across tissues. Appropriate positive controls such as spleen tissue should be included .

• Cross-reactivity concerns: Given the 69% sequence identity between PDIK1L and STK35, careful antibody selection is crucial for distinguishing between these paralogs. Antibodies targeting unique regions can help discriminate between these proteins .

• Validation approaches: Confirm specificity through knockout controls, peptide competition assays, or recombinant protein standards such as the full-length human PDIK1L recombinant protein expressed in baculovirus-infected Sf9 cells .

PDIK1L in Complex Signaling Networks

Recent research has revealed that PDIK1L functions within a sophisticated nuclear signaling network. A pivotal discovery is the interaction between PDIK1L and the nuclear phosphatase SCP4 . This interaction forms a dual phospho-catalytic signaling complex with significant implications for cellular regulation.

The SCP4-PDIK1L complex demonstrates a unique regulatory mechanism whereby:

• SCP4 regulates PDIK1L through two distinct mechanisms:

  • Catalytic removal of inhibitory phosphorylation

  • Promotion of kinase activity

• This interaction specifically occurs with the catalytically active form of SCP4

• The complex localizes predominantly to the nucleus, suggesting nuclear-specific signaling functions

Importantly, this interaction can be detected and studied through co-immunoprecipitation experiments using either SCP4 or PDIK1L antibodies, followed by western blot or mass spectrometry analysis .

Role in Pathological Conditions

PDIK1L has emerged as a significant factor in acute myeloid leukemia (AML) biology. Research indicates that:

• PDIK1L functions redundantly with its paralog STK35 in maintaining AML proliferation

• The SCP4-STK35/PDIK1L complex supports critical cellular processes including amino acid biosynthesis and transport

• Expression levels of STK35/PDIK1L correlate with disease progression and prognosis in several tissue contexts

This involvement in AML presents PDIK1L as a potential therapeutic target or biomarker, necessitating reliable antibodies for both research and potential clinical applications.

Experimental Design for PDIK1L Functional Studies

For researchers investigating PDIK1L function, several experimental approaches have proven effective:

• Genetic manipulation studies: CRISPR-Cas9 technology has been successfully employed to understand PDIK1L function. Domain-focused CRISPR screening and exon scanning approaches have revealed critical insights about PDIK1L's catalytic function .

• Interaction profiling: Mass spectrometry analysis of affinity-purified complexes has identified binding partners of PDIK1L, with SCP4 being a significant interactor. This approach requires careful antibody selection and optimization of purification conditions .

• Functional assays: BrdU incorporation measurements and annexin V staining have been used to assess the effects of PDIK1L dysregulation on cell cycle progression and apoptosis .

• Rescue experiments: Complementation with sgRNA-resistant cDNA constructs has been utilized to confirm on-target effects of PDIK1L knockout, providing important validation of observed phenotypes .

Integration of Multi-omics Approaches

The advancement of our understanding of PDIK1L function will likely benefit from integrated multi-omics approaches. This could include:

• Phosphoproteomics to identify PDIK1L substrates and downstream signaling targets

• Transcriptomic analysis to understand gene expression networks regulated by PDIK1L

• Interactome mapping to comprehensively characterize the PDIK1L protein interaction network

These approaches would benefit from high-quality, validated PDIK1L antibodies for techniques like ChIP-seq, though previous attempts have not identified evidence of sequence-specific DNA occupancy .

Therapeutic Potential and Translational Applications

Given the involvement of PDIK1L in AML and potentially other diseases, research into its therapeutic targeting is warranted. This may involve:

• Development of small molecule inhibitors specific to PDIK1L

• Exploration of the SCP4-PDIK1L interaction as a potential drug target

• Investigation of PDIK1L as a biomarker in various disease contexts

These translational efforts will rely heavily on well-characterized antibodies for validation studies, diagnostic development, and therapeutic monitoring.